Protective device.



I. J. FRANK.

PROTECTIVE DEVICE.

APPLICATION FILED JUNE 6,1913.

1,172,972. Patented Feb. 22,1916.

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m llI l II Inventor: John LPI-ank,

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MMX@- THE COLUMBIA PLANOGRM'H co.. WASHINGTON. D. c.

UNITED STATES PATENT OFFICE.

JOHN J. FRANK, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK.

PROTECTIVE DEVICE.

Specification of Letters Patent.

Patented Feb. 22, 1916.

Application led June 6, 1913. Serial No. 772,161.

To all whom it may concern Be it known that I, JOHN J. FRANK, al citizen of the United States, residing at Pittsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Protective Devices, of which the following is a specification.

My invention relates to protective devices for electrical installations, and in particular to devices for protecting electrical apparatus, such as transformers, included in a high voltage electrical transmission system.

More specifically, my invention relates to that type 0f protective device described in the application for United States Letters Patent of Dr. Charles P. Steinmetz, filed June 19, 1913, Serial No. 774,513.

The patent application above mentioned describes a protective device selec tive in its action and permitting a nonoscillatory flow of high frequency current coming from one direction but reflecting back toward the source high frequency current coming from the other direction. The device is adapted to be employed in an electrical installation, comprising two sections, each section having distributed resistance, inductance and capacity, and consists of an inductance included in series relation with the installation and shunted by a resistance whose ohmic value is approximately equal to the ohmic value 0f the surge resistance of that section of the installation to be protected. As explained in the above mentioned patent application, such a protective device permits the non-oscillatory exit of Vhigh frequency disturbances arising within the section of the installation to be protected and reflects back toward the sourcev high frequency disturbances arising in the other section.

The object of my invention is to provide a 1 novel construction and arrangement of apparatus particularly adapted to perform the functions of the protective device above described.

More generally, the object of my invention is to provide a novel and compact arrangement of inductive winding and a non-inductive winding in a single unitary structure.

A further object of my invention is to provide a non-inductive resistance of novel and improved construction.

The features of my invention which I believe to be novel and patentable are definitely indicated in the claims appended hereto.

The construction and arrangement of apparatus in a protective device embodying the novel features of my invention will be understood from the following` description taken in connection with the accompanying drawings, in which:

Figure 1 is an elevation partly in section of a protective device embodying my invention, and Fig. 2 is a diagrammatic representation of my protective device operatively connected in an electrical installation.

Referring first to Fig. 2 of the drawings, it will be observed that my protective device is arranged to protect the windings of a transformer This transformer is included in an electrical installation and has its high potenti-al winding connected to transmission conductors 6. Translating devices of any desired character may be connected to the transmission conductors 6. Such devices have been omitted in the drawings in order to simplify the showing.

An inductive winding 7 is included in series relation with one of the transmission conductors, and this winding is shunted by a non-inductive resistance 8. The ohmic value of the non-inductive resistance 8 is approximately equal to the ohmic value of the surge resistance of the transformer 5. As explained in the hereinbefore mentioned patent application of Dr. Steinmetz, the ohmic value of the surge resistance of the transformer is equal to where L and C represent in henries and farads the inductance and capacity respectively of the transformer. As the surge resistance of the transformer is many times greater than the surge resistance of the transmission conductors, the protective device comprising the inductance 7 and noninductive resistance S will act to permit the non-oscillatory exit of any high frequency disturbance arising within the transformer and to reflect back toward the source any high frequency disturbance arising without the transformer. It will of course be understood that I may insert a protective device in each transmission conductor if desired. The resistance 8 should have substantially no inductance and to this end I have found it most desirable to employ a liquid resistance. rl`he combination ot a liquid resistance in a protective device ot the type herein described, l consider to be an important feature. of my invention. l have furthermore devised'a novel construction of liquid rheostat which is peculiarly adapted to perlferm the functions ot the resistance in tl e protective device to which my invention reates. rlhe details of construction ot this iauid rheostat will be understood from the lowing description.

1n 1 of the drawings, l have illustrated a protective device orp unitary construction embodying the inductance 7 and resistance S of Fig. This protective device comprises a supporting base 10 of insulating material upon which are mounted concentric cylinders 11 also of insulating material. Preferably l construct the cylinders 11 ot' concrete or other stone-ware material. 'lhe inductance comprises a winding of bare copper wire 12, wound upon the cylinders 11. rlhe terminals of this inductive winding are indicated at 13 and 14: respectively. Porcelain sleeves 15 are mounted on the wire 12 and serve to space the turns ot the winding from each other and also to space the wire conductors from the supporting cylinders.

i liquid containing vessel 16 is arranged within the inner cylinder 11 and rests upon the supporting base 10. This vessel contains a liquid electrolyte 17 which serves as the resistance material of the liquid rheostat. Preferably the electrolyte consists of a mixture ot' water, salt and glycerin, the salt being added to obtain a certain ohmic value of the liquid, and the glycerin being added to prevent the mixture from freezing at low temperature.

A tubular member 1S is mounted within the vessel 16 and serves to divide the electrolyte in the vessel into two portions. The bottom ot the tubular member does not reach to the bottom of the vessel, and the electrolyte at the bottom of the vessel theretore serves to electrically connect the portions of the electrolyte divided by the tubular member. The vessel 16 and tubular member 18 are preferably of stone-ware material. The dielectric strength of this material is not very great, and l have accortiingly found it desirable to provide another insulating material between the two portions oi' electrolyte. This l accomplish by providingthe tubular member with a double wall forming a liquid containing chamber. lnsulating liquid 19, such as oil, is inserted in this chamber.

lin electrode 20 is supported on inwardly projecting shoulders near the top of the vessel 1G and extends into the electrolyte between the vessel and the tubular member,

thus constituting one terminal ont the liquid rheostat. rlChis electrode is connected to the terminal iet of the inductance by means ot a conductor 21. in adjustable electrode 22 extends into the electrolyte within the tubular member 18 and constitutes the other terminal of the liquid rheostat. rl`his electrode is adapted to be connected to the terminal 13 ot the inductance.

lt will be seen that the tubular member 18 provides a plurality ot paths tor the iow of current through the electrolyte. lt the current is assumed to enter at the electrode 20, it will fiow downwardly in that portion ot the electrolyte surrounding the tubular memer to the bottom of this member, and then upwardly through that portion ot' the electrolyte within the tubular member. The layer of insulating liquid supported by the double wall construction oi tiie tubular mem- .ber insulates the portion ot the electrolyte within the tubular member from the electrolyte surrounding the tubular member, except at the bottom of the tubular member where these two portions of electrolyte are electrically connected.

The top orl the vessel 1G is closed by a cover of stoneware material :23. rlhe electrode 22 is supported by an insulating cap 2l which rests upon the cover 23. The upper portion 27 ot the outer wall ot the tubular member is of increased diameter and into the space between the two walls of this member a downwardly projecting battle plate 2G extends. This plate is supported by the cover Q3 and may be made integral therewith.

What l claim as new and desire to secure by Letters Patent of the United States, is

1. rlhe combination with a spiral inductive winding and a supporting base for one end ot said winding, ot a vessel mounted within said winding upon said support and containing an electrolyte, an annular container mounted within said vessel to project into said electrolyte and adapted to contain insulating liquid in the space between its walls, an electrode mounted inside of said annular container, and a second electrode mounted outside of said container.

The combination of a spiral inductive winding, a vessel mounted within said winding and containing an electrolyte, a container mounted within said vessel to divide the electrolyte into two electrically connected portions and containing liquid insulating material for insulating said portions of the electrolyte, and electrodes extending into said portions ot said electrolyte, said electrodes being connected to diiierent points on said winding.

3. The combination with a cylinder of insulating material having a winding inductively wound thereon and a supporting base, of a vessel mounted within said cylinder and containing an electrolyte, means for supporting a mass of liquid insulating material Within said vessel in position to divide the electrolyte therein into electrically connected portions, and electrodes extending into said portions of said electrolyte and connected to diiferent points on said Winding.

4. The combination with a. cylinder of insulating material having a Winding inductively Wound thereon and a supporting base, of a liquid containing vessel Within said cylinder and resting on said support, trode arranged to extend into the electrolyte extending into said electrolyte and adapted to be operatively connected to said winding, and a chamber containing insulating liquid and mounted in said vessel to separate said electrodes by an insulating Wall comprising part of said insulating llquid.

5. The combination with a cylinder of insulating material having a Winding inductively Wound thereon and a supporting base, of a liquid containing vessel Within said cylinder and resting upon said support, an electrolyte Within said vessel, a tubular member having a surrounding liquid containing chamber Within said vessel, an insulating liquid in said chamber, an electrode arranged to extend into the electrode between the vessel `and the tubular member, and a second electrode arranged to extend into the electrolyte Within said tubular member.

In Witness whereof, I have hereunto set my hand this 4th day of June, 1913.

JOHN J. FRANK.

Witnesses:

A. K. NUGENT, H. NUGENT.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

